The invention refers to a portable lighter of the type that is apt for reaching a state of ignition and having a lighting mechanism adequate to be activated by means of one single finger movement, with said finger presenting a resistance to deformation. The mechanism consists of at least a first actuator and a second actuator, this first actuator being apt to move between a first position and a second position, and the second actuator being apt for moving between a third position and a fourth position, where the second position and the fourth position define a relative position between the first actuator and the second actuator.
In recent years the use of lighters has become extraordinarily popular, no longer being luxury items or of personal use, and therefore submitted to a direct control on the part of the user, becoming abundantly available objects, that may be found indiscriminately in any place of a house, vehicle or facility. Likewise, as they are devices designed to produce a flame, awareness has increased of the implicit danger of their use by children, especially when these are away from adult supervision. Thus, different models of lighters with safety mechanisms have appeared on the market with the object of increasing the degree of protection in this sense.
The first solutions available for the technical challenge involved in making the lighting more difficult for children, without excessively complicating the use for adults, consisted of placing retractable elements under the button of the gas valve, impeding its activation course unless previous to the intention of lighting they were moved from their normal inhibiting position to another in which they would not be an obstacle to the movement of the former. Clearly representing this period of time are inventions such as those described in the registrations U.S. Pat. No. 5,002,482 or U.S. Pat. No. 5,090,893 in the case of wheel and pyrophoric stone lighters, or EP 488,158 in the case of piezoelectric lighters.
The additional safety that these models provide is based on adding to a conventional ignition movement or action another previous action consisting in moving a retractable element to a non-inhibiting position. Lighters with a safety mechanism that follow this principle are known as xe2x80x9cdual-actionxe2x80x9d lighters. Regrettably, in the case of pocket lighters, due to their small size, these retractable elements must be tiny, and while it is true that they provide additional safety, they undeniably possess a difficulty of operation for adults also which in some cases can become insuperable, especially for those who are less capable with their handling abilities. Furthermore, since they are based on the correct performance of visible actions, they are easily imitated by children, which reduces the efficacy of the protection.
The appearance of xe2x80x9csingle actionxe2x80x9d lighters provided an interesting solution to the problems mentioned in the previous paragraph. They are not based on the accumulation of actions as a consequence of adding complementary mechanisms, but rather in taking advantage, based on a correct positioning of the conventional igniting elements, of the ergonomic differences between children and adults.
A first generation of xe2x80x9csingle actionxe2x80x9d lighters is well represented in registration U.S. Pat. No. 5,490,773. This requires performing movements on the conventional igniting elements that are difficult for children to perform, due to the geometric characteristics of their fingers. Furthermore, due to the scarce extent of these movements they are not visible, and thus they cannot be learned by imitation.
The object of this Patent application is a second generation of xe2x80x9csingle actionxe2x80x9d lighters, that is, lighters that can be lit by means of one single movement. It is based on the difference of hardness of a child""s fingertip and that of an adult, understanding hardness to be the resistance that a surface provides to the penetration or the deformation of an object. At higher penetration or higher deformation under the same contact force, it is understood that the surface is less hard.
The reason of this lower hardness of a child""s fingertip with respect to an adult""s is a consequence of the different cell characteristics and the thickness of the skin, the underlying tissue and especially the smaller size of the internal bones (phalanxes), which confer consistence to them. The invention object of this application will take advantage of this universal ergonomic difference.
The invention described in this Patent application uses this relative difference in hardness, in cooperation with an adequate design of the constituting elements of the lighting mechanism, to enable or impede reaching a state of ignition.
This purpose is attained by means of a portable lighter of the type mentioned at the beginning, characterized in that when moving by means of a finger the first actuator from the first position to the second position, said finger moves the second actuator from the third position to the fourth position, where the relative position between both actuators in said second and fourth position is variable depending on the resistance to the deformation of the finger, and in that said portable lighter reaches the state of ignition only for certain preset values of said relative position.
Thus, in the case of each specific lighter it is possible to calculate or measure the relative positions that are reached when the lighter is being handled by an adult and the relative positions that are reached when the lighter is being handled by a child, and from this data the internal mechanisms of the lighter can be developed and adjusted. It must also be taken into account that it is possible to influence over the values of these relative positions in various ways, by varying the geometries of movement, the support surfaces, the spring characteristics, etc.
A preferred embodiment is obtained by making the fourth position variable depending on the mentioned resistance to deformation with the second position being substantially independent from said resistance to deformation, and therefore the mentioned relative position is made variable depending on said fourth position. It must be understood in this case that small possible differences in said second position due to construction matters not related to the object of this invention must not be considered as conceptually different second positions from the viewpoint of the invention.
In the case of lighters of the type that have an energy generator apt for liberating an ignition energy and that require that said ignition energy arrives to an ignition zone to reach said state of ignition, a preferred type of embodiment of the invention is obtained when the first actuator acts upon the energy generator, which liberates the ignition energy and when the second actuator, in said certain preset values of said relative position, allows the ignition energy to get to said ignition area.
Preferably said ignition energy is apt to cause the ignition of a combustible fluid, as is usual in the majority of lighters which incorporate a canister with combustible fluid and in which the state of ignition is characterized by a flame. However, other types of lighters should not be dismissed, in which, for example, an electric resistor is heated to incandescence and it is directly used for lighting, for example, a cigarette, by direct contact of the cigarette with the incandescent resistor or simply by proximity of the cigarette to the incandescent resistor.
The object of the invention can be applied to a multitude of practical embodiments, such as:
that said energy generator is a pyrophoric stone, and that said ignition energy is a spark, in which case, preferably, the second actuator inserts a shield between said spark and said ignition zone when said relative position is any other than one of said preset values.
that said energy generator is an electric battery, and that said ignition energy is an electric current that heats an electric resistor, in which case, preferably, the second actuator diverts or, alternatively, inhibits said electric current avoiding that this electric resistor heats up when said relative position is any other than one of said preset values.
that said energy generator is a piezoelectric mechanism, and that said ignition energy is a spark, in which case, preferably, the second actuator diverts said spark from the piezoelectric element to an inert area away from the ignition zone when said relative position is any other than one of said preset values.
that said energy generator is an electric battery and that said ignition energy is an electric current which generates a spark, in which case, preferably, the second actuator diverts said electric current avoiding that the spark is formed when said relative position is any other than said preset values. These lighters usually include, additionally, a circuit apt to increase the electric voltage in the battery terminals to certain values apt for generating a spark. However, said circuit does not have any influence on the object of the invention, so it is not taken into account in what follows.
Another preferred embodiment of the invention in lighters that have an energy generator apt to liberate an ignition energy to reach said ignition state, is obtained by making the second actuator act on said energy generator, which only liberates the ignition energy when said second actuator reaches said certain preset values of said relative position. In this case the ignition energy is not impeded from getting to the ignition area, but rather the formation of said ignition energy is directly impeded, as, for example, in a piezoelectric lighter in which the piezoelectric device, activated by the second actuator, does not reach the position in which the spark is generated.
Finally another embodiment of the invention is attained when the combustible fluid only arrives at the ignition zone if said certain preset values of said relative position are reached. In fact, the lighters that have a state of ignition with a flame, said state of ignition can be avoided, avoiding that the combustion of the combustible fluid starts or by avoiding the release of the combustible fluid from the corresponding canister by which, although the ignition energy, for example the spark, is produced and is present at the ignition area, however, the lack of combustible fluid will avoid the flame from being produced.